git-etc: remove all code.

I've given up on this; too many edge cases.
If someone else wants to pick it up then send me a message and I'll walk
you through the approach.

Library/Homebrew/formula.rb

@@ -169,10 +169,7 @@ class Formula
   # generally we don't want var stuff inside the keg
   def var; HOMEBREW_PREFIX+'var' end
 
-  def bash_completion
+  def bash_completion; prefix+'etc/bash_completion.d' end
-    etc = ENV['HOMEBREW_GIT_ETC'] ? self.etc : prefix+'etc'
-    etc+'bash_completion.d'
-  end
   def zsh_completion;  share+'zsh/site-functions'     end
 
   # for storing etc, var files for later copying from bottles

Library/Homebrew/formula_installer.rb

@@ -73,76 +73,6 @@ class FormulaInstaller
     raise
   end
 
-  def git_etc_preinstall
-    return unless quiet_system 'git', '--version'
-
-    etc = HOMEBREW_PREFIX+'etc'
-    etc.cd do
-      quiet_system 'git', 'init' unless (etc+'.git').directory?
-      quiet_system 'git', 'checkout', '-B', "#{f.name}-preinstall"
-      unless quiet_system 'git', 'diff', '--exit-code', 'HEAD'
-        system 'git', 'add', '--all', '.'
-        system 'git', 'commit', '-m', "#{f.name}-#{f.version}: preinstall"
-      end
-
-      unless quiet_system 'git', 'rev-parse', 'master'
-        quiet_system 'git', 'branch', 'master'
-      end
-    end
-  end
-
-  def git_etc_postinstall
-    return unless quiet_system 'git', '--version'
-
-    preinstall_branch = "#{f.name}-preinstall"
-    default_branch = "#{f.name}-default"
-    merged = false
-    f.etc.mkpath
-    f.etc.cd do
-      if quiet_system 'git', 'diff', '--exit-code', preinstall_branch
-        quiet_system 'git', 'branch', default_branch
-        quiet_system 'git', 'branch', '-D', preinstall_branch
-      elsif not quiet_system 'git', 'rev-parse', default_branch
-        quiet_system 'git', 'checkout', '-B', default_branch
-        quiet_system 'git', 'add', '--all', '.'
-        system 'git', 'commit', '-m', "#{f.name}-#{f.version}: default"
-        quiet_system 'git', 'branch', '-D', preinstall_branch
-      else
-        previous_default_branch = `git rev-parse #{default_branch}`.strip
-        quiet_system 'git', 'checkout', '-B', default_branch
-        quiet_system 'git', 'add', '--all', '.'
-        system 'git', 'commit', '-m', "#{f.name}-#{f.version}: default"
-
-        default_unchanged = quiet_system('git', 'diff', '--exit-code', \
-                                                previous_default_branch)
-
-        if default_unchanged
-          system 'git', 'reset', '--hard', previous_default_branch
-        end
-
-        quiet_system 'git', 'checkout', 'master'
-        quiet_system 'git', 'reset', '--hard', preinstall_branch
-
-        unless default_unchanged
-          merge_ff = quiet_system 'git', 'merge', '--ff-only', '--no-edit',
-                                         '-X', 'ours', default_branch
-          unless merge_ff
-            merged = true
-            system 'git', 'merge', '--no-ff', '--no-edit',
-                          '-X', 'ours', default_branch
-          end
-        end
-      end
-
-      if merged
-        ohai "Configuration Files"
-        puts "Your configuration files for #{f.name} in etc were merged:"
-        puts "To reverse this merge: git reset --hard #{preinstall_branch}"
-        puts "To restore defaults:   git reset --hard #{default_branch}"
-      end
-    end
-  end
-
   def build_bottle_preinstall
     @etc_var_glob ||= "#{HOMEBREW_PREFIX}/{etc,var}/**/*"
     @etc_var_preinstall = Dir[@etc_var_glob]
@@ -183,8 +113,6 @@ class FormulaInstaller
 
     @@attempted << f
 
-    git_etc_preinstall if ENV['HOMEBREW_GIT_ETC']
-
     @poured_bottle = false
 
     begin
@@ -221,8 +149,6 @@ class FormulaInstaller
       opoo "#{f.name} post_install failed. Rerun with `brew postinstall #{f.name}`."
     end
 
-    git_etc_postinstall if ENV['HOMEBREW_GIT_ETC']
-
     opoo "Nothing was installed to #{f.prefix}" unless f.installed?
   end
 

Library/Homebrew/install_renamed.rb

@@ -15,7 +15,7 @@ module InstallRenamed
   private
 
   def append_default_if_different src, dst
-    if File.file? dst and !FileUtils.identical?(src, dst) and !ENV['HOMEBREW_GIT_ETC']
+    if File.file? dst and !FileUtils.identical?(src, dst)
       dst += ".default"
     end
     dst